<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8" />
		<title></title>
		<style type="text/css">
			.big-div{
				width: 500px;
				height: 500px;
				background-color: lightpink;
			}
			.small-div{
				  border-style: solid;
            border-width: 0px 0px 100px 100px;
            border-color: transparent transparent blue transparent;
            width: 0px;
            height: 0px;
			}
		</style>
	</head>
	<body>
		<div class="big-div">
			<div class="small-div"></div>
		</div>
	</body>
</html>
